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Large Asteroid to Fly Past Earth
Written by Jeanna Bryner of Space.com   
Thursday, 24 January 2008
2007 TU24An asteroid that's likely as big as several football fields will fly past Earth next week. Astronomers said the space rock will be visible the night of Jan. 29 to amateur astronomers with modest-sized telescopes.

Called 2007 TU24, the asteroid was discovered by NASA's Catalina Sky Survey on Oct. 11, 2007. It is estimated to be somewhere between 500 feet (150 meters) to 2,000 feet (610 meters) in diameter.

The asteroid makes its closest approach to Earth, 334,000 miles (537,500 kilometers), at 3:33 a.m. Eastern time (12:33 a.m. Pacific time). For comparison, the moon is an average of 239,228 miles (385,000 kilometers) away.

"This will be the closest approach by a known asteroid of this size or larger until 2027," said Don Yeomans, manager of the Near Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif.

However, that doesn't mean we won't hear about another flyby of this nature before then. With relatively small space rocks, like this one, astronomers sometimes don't know they're passing through until right before they do.

There is no danger of the asteroid striking Earth in the foreseeable future, the scientists said.

But if an asteroid with this size were to hit Earth, the results could be regionally devastating. The impact itself would release about 1,500 megatons of energy, creating a crater about three miles (nearly five kilometers) wide and kicking up loads of debris, according to Yeomans.

"If it hit in the ocean, which is more likely because two thirds of the Earth is ocean, it would create a tsunami, which would be devastating for the coastlines that happen to be nearby," Yeomans told SPACE.com. "It would be a huge local problem and the tsunami would be extraordinary if it hit in the ocean."

"As its closest approach is about one-and-a-half times the distance of Earth to the moon, there is no reason for concern," Yeomans said. "On the contrary, Mother Nature is providing us an excellent opportunity to perform scientific observations."

At its nearest, the asteroid will reach an approximate apparent magnitude 10.3, which is about 50 times fainter than an object visible to the naked eye in a clear, dark sky. Then, it will quickly become fainter as it moves away.

Like other asteroids, this one orbits the sun. Most do so in the asteroid belt between Mars and Jupiter. NASA pays particular attention to those whose orbits bring them so close to Earth.

Given the estimated number of near-Earth asteroids of this size (about 7,000 discovered and undiscovered objects), astronomers would expect an object of this size to pass this close to Earth every five years or so on average. And about every 37,000 years on average, an object this size would be expected to actually impact Earth.

Astronomers have catalogued hundreds of asteroids larger than a half-mile across that pass in the vicinity of Earth's orbit. However, none of these are known to be on a collision course with our planet.
Last Updated ( Saturday, 26 January 2008 )
 
Merry Christmas!
Written by Angel   
Monday, 24 December 2007
I would just like to take this opportunity to wish everyone who bothers with this site a very Merry Christmas and a Happy New Year!
 
May 2008 bring you way more cool crap then 2007 ever did...
 
Eh... You get the picture. ;) Thanks for visiting and thank you all for your emails. I really appreciate all the support I've gotten from all you guys. Thanks a lot.
 
I'll be throwing more junk here soon as time allows. ;) 
 
Einstein's Warping Found Around Neutron Stars
Written by Space.com   
Tuesday, 28 August 2007

An artist depicts a disk of hot gas whipping around a neutron star. The gas in the inner part of the disk whirls around so fast that it experiences effects predicted by Einstein's theories of relativity. Credit: NASA/Dana Berry.Einstein's predicted warping of space-time has been discovered around neutron stars, the most dense observable matter in the universe.

The warping shows up as smeared lines of iron gas whipping around the stars, University of Michigan and NASA astronomers say. The finding also indicates a size limit for the celestial objects.

The same distortions have been spotted around black holes and even around Earth, so while the finding may not be a surprise, it is significant for answering basic questions of physics, said study team member Sudip Bhattacharyya of NASA's Goddard Space Flight Center in Greenbelt, Md. and the University of Maryland, College Park.

"This is fundamental physics," Bhattacharyya said. "There could be exotic kinds of particles or states of matter, such as quark matter, in the centers of neutron stars, but it's impossible to create them in the lab. The only way to find out is to understand neutron stars."

Neutron stars can pack more than a sun's worth of material into a city-sized sphere. A few cups of neutron-star stuff would outweigh Mount Everest. Astronomers use these collapsed stars as natural laboratories to study how tightly matter can be crammed under the most extreme pressures nature can offer.

To even begin to address the mystery of what lies within these dying stars, scientists must accurately and precisely measure their diameters and masses.

In two concurrent studies, astronomers used the European Space Agency's XMM-Newton X-ray Observatory and the Japanese/NASA Suzaku X-ray to survey three neutron-star binaries: Serpens X-1, GX 349+2 and 4U 1820-30. They also studied the spectral lines from hot iron atoms that whirl around in a disk just beyond the neutron stars' surfaces at speeds reaching 40 percent light speed.

Normally, the measured spectral line for the superheated iron atoms would show up as a symmetrical peak. However, their results showed a skewed peak that was indicative of distortion due to relativistic effects. The extremely fast motion of the gas (and the related powerful gravity), they say, causes the line to smear, shifting it to longer wavelengths.

The measurements allowed them to determine maximum star size. "We're seeing the gas whipping around just outside the neutron star's surface," said XMM-Newton team member Edward Cackett of the University of Michigan. "And since the inner part of the disk obviously can't orbit any closer than the neutron star's surface, these measurements give us a maximum size of the neutron star's diameter."

He said the neutron stars can be no larger than about 20.5 miles (33 kilometers) across.

The XMM-Newton paper was published in the Aug. 1 issue of Astrophysical Journal Letters. The other paper has been submitted for publication in the same journal.

Last Updated ( Saturday, 26 January 2008 )
 
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